Marking film and composite marking film

ABSTRACT

A marking film exhibiting good ability for tracing curved surfaces when it is to be stuck to steeply curved three-dimensional portions without entrapping air bubbles at the film edges when an over-clear coating is applied thereon after it has been stuck. The marking film has a marking component to be transferred onto an article via an adhesive layer, wherein the total thickness of the marking film is in the A range of from about 50 μm to about 300 μm, and the modulus of elasticity thereof is in the range of from about 2 kgf/mm 2  to about 25 kgf/mm 2  as measured under a condition where the marking film is elongated at a tension speed of 300 mm/min. into an elongation percentage in the range of 0 to about 10%.

FIELD OF THE INVENTION

The present invention relates to a marking film. More specifically, theinvention relates to an improved marking film which can be transferredand adhered onto articles having rugged surfaces and steeply curvedthree-dimensional surfaces, favorably and with ease, without developingpoor appearance caused by the entrapment of air bubbles at the ends ofthe film when an over-clear coating is applied onto the marking film.The invention also relates to a composite marking film comprising acombination of the marking film and the application film, exhibitingexcellent effects of the marking film and enhancing the workability. Theinvention, therefore, can be advantageously used for adhering themarking film having a predetermined shape or ornament appeal(hereinafter referred to as “marking component”) onto articles such asautomobiles, motorcycles, etc. and onto any other articles.

BACKGROUND

In order to assist the operation for transferring and adhering a markingfilm onto an article having curved surfaces and rugged portions, therehave heretofore been used various types of transfer-assisting memberscalled application films or application tapes. Japanese UnexaminedPatent Publication (Kokai) No. 6-51702 discloses an application tapewhich can be transferred onto a desired article by peeling an ornamentaladhesive sheet of a predetermined shape off a peel member, the basemember of the tape having a 2% modulus value of 3 to 4 kg/15 mm of widthand an elongation percentage at breakage of not smaller than 50% whenthe tension speed is 0.2 m/min.

Japanese Unexamined Patent Publication (Kokai) No. 7-138540 discloses anapplication film for a marking sheet having an adhesive layer formed onone surface of a base member of a thermoplastic resin and is used forapplying a marking sheet, wherein the base member is more flexible thanthe marking sheet and has rich rubbery elasticity. Desirably, the basematerial of the application film is a soft vinyl chloride resin.Besides, the film desirably has a 10% modulus of 1.5 to 2.5 g/25 mm ofwidth, a maximum elongation of 150 to 300% and a thickness of 50 to 100μm. The adhesive layer has a thickness of 10 to 20 μm.

In recent years, however, it has been desired to stick the marking filmonto ever steeply curved portions in the field of armoring such as, fueltanks of motorcycles, fenders, etc. However, such requirements cannot besufficiently met by the application films disclosed in theabove-mentioned Unexamined Patent Publications. That is, on the portionsof complex shapes such as fuel tanks, fenders, etc., the stickingoperation must be carefully carried out so that wrinkles will notdevelop and air bubbles will not be entrapped, particularly, as theareas of such portions increase, resulting in a great decrease in thesticking operation efficiency, In order to improve the efficiency ofsticking operation, it can be contrived to decrease the thickness of themarking film to cope with to various curved shapes or, in other words,to enhance the “ability for tracing curved surfaces”. However, such athin film is likely to be damaged during the work and, besides, losesthe so-called “stiffness”, deteriorating the workability, causing thepositioning to become complex and often permitting the films to beadhered to each other during the work. Moreover, despite the operationis carefully done, wrinkles develop and air bubbles are inevitablyentrapped. Besides, due to a complex shape of a portion where the filmis to be stuck, the marking film after stuck is often damaged despite itwas carefully stuck.

Moreover, in order to further improve the ornamental appeal or toprotect the marking film applied to the article from being rubbed orpeeled, an over-clear coating is often applied onto the marking film.Here, a problem stems from a step formed at the end of the film. Whenthe marking film is thick, air bubbles are entrapped in the steppedportions to deteriorate appearance. Or, it often becomes necessary tostick the marking film all over again.

SUMMARY OF THE INVENTION

The present invention provides an improved marking film that is freefrom one or more of the above-mentioned problems inherent in the priorart. The present marking film can be transferred and adhered ontoarticles having rugged surfaces and steeply curved three-dimensionalsurfaces favorably and with ease. The present marking film does notcause the appearance to be deteriorated that stems from the entrappingof air bubbles at the ends of the film.

According to one aspect of the present invention, there is provided amarking film having a marking component to be transferred onto anarticle via an adhesive layer, wherein a total thickness of the markingfilm is in the range of from about 50 μm to about 300 μm, and themodulus of elasticity thereof is in the range of from about 2 kgf/mm² toabout 25 kgf/mm² as measured under a condition where the marking film iselongated at a tension speed of 300 mm/min. into an elongationpercentage in the range of from 0 to about 10%.

According to another aspect of the present invention, there is provideda composite marking film comprising a marking film having a markingcomponent to be transferred onto an article via an adhesive layer, andan application film used as a transfer-assisting member when the markingfilm is to be transferred onto the article, wherein the modulus ofelasticity of the composite marking film is in the range of from about 2kgf/mm² to about 28 kgf/mm² as measured under a condition where thecomposite marking film is elongated at a tension speed of 300 mm/min.into an elongation percentage in the range of from 0 to about 10%.

The present inventors have conducted study in an attempt to solve theproblems of the conventional application films or of the marking filmsused in combination therewith, as described above in the Backgroundsection, have discovered the fact that the problems can be solved uponimproving the marking film rather than the application film and,particularly, upon improving the properties of the marking film, andhave thus completed the marking film of the present invention.

As a result of the study conducted thus far, the study group of thepresent inventors has accomplished an application film as disclosed in,for example, Japanese Unexamined Patent Publication (Kokai) No.10-287849. This application film is used as an intermediate transfermember when the marking member is to be adhered onto the article, andcomprises a base member and an adhesive layer formed on one surface ofthe base member and can be adhered to the marking member, the basemember having a 10% modulus strength of from 0.3 to 1.6 kgf/25 mm, a 10%modulus stress of from 0.1 to 0.8 kgf/mm², a 100% modulus stress of from0.7 to 2.5 kgf/mm², and a rate of change in the modulus stress of notsmaller than 0.3 when measured at a tension speed of 200 mm/min. incompliance with the standards stipulated under Japanese IndustrialStandard (JIS)-K7127. Owing to particular properties of the base memberthat is used, the application film exhibits flexibility, rubberyelasticity and stiffness which are well balanced, and can beadvantageously used as an intermediate transfer member at the time whenthe marking member is to be adhered, particularly, onto steeply curvedthree-dimensional surfaces of the articles. In using the applicationfilm, the inventors have forwarded the study concerning which markingmember or, in other words, which marking film would be effective whenthe article has steeply curved three-dimensional surfaces, and havediscovered that the marking member having suitable degrees offlexibility and rubbery elasticity is desirable. According to thepresent invention, the thickness and the modulus of elasticity at anelongation percentage of from 0 to 10% of the marking film are limitedto lie within particular ranges, making it possible to improve theability for tracing the three-dimensional curved surfaces. Even when themarking film is accompanied by the application film, the modulus ofelasticity of the whole film at an elongation percentage of from 0 to10% is limited to lie within a particular range to obtain the sameeffect. In addition, according to the present invention, the degree ofability for tracing the curved surfaces can be easily estimated from aformula of a primary function as will be described later in detail. Uponimposing limitation on the thickness of the marking film, furthermore,the over-clear coating can be applied without causing any trouble afterthe marking film has been stuck. According to the application filmdisclosed in the above-mentioned Japanese Unexamined Patent Publication(Kokai) No. 7-138540, it is essential to use a hard marking sheet havingflexibility and rubbery elasticity inferior to those of the applicationfilm, which is contrary to those of the present invention.

Besides, the present inventors have discovered that the application filmused in combination therewith plays an important role of maximizing theexcellent action and effect exhibited by the marking film, and havecompleted the composite marking film of the present invention to obtainexcellent effect stemming from the combination of the two films.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating a preferred marking film and apreferred composite marking film according to the present invention.

FIG. 2 is a sectional view illustrating an example where the markingfilm of the invention is stuck to an article having a curved surface andan over-clear coating is further applied thereon.

FIG. 3 is a graph plotting the relationships between the area ratios andthe moduli of elasticity of the composite marking films.

FIG. 4 is a graph plotting the relationships among the combinations ofthe composite marking films, the area ratios and the moduli ofelasticity.

FIG. 5 is a graph plotting the relationships between the combinations ofthe composite marking films and the moduli of elasticity.

DETAILED DESCRIPTION

FIG. 1 is a sectional view illustrating a preferred marking filmaccording to the present invention and a preferred composite markingfilm including the marking film. For easy comprehension, this viewillustrates the films on an enlarged scale.

A marking film 3 comprises a base member 1 and an adhesive layer 2formed on one surface of the base member 1 and can be adhered to anarticle (not shown). Though not illustrated, it is desired that thesurface of the adhesive layer 2 is provided with a peeling paper toprotect the layer until it is applied to the article, as is widely donein this field of art.

In the practice of the present invention, the marking film 3 has a totalthickness (sum of the thicknesses of the base member 1 and the adhesivelayer 2, or inclusive of the thickness of any additional layer) of from50 to 300 μm. The marking film 3 has a modulus of elasticity in a rangeof from 2 to 25 kgf/mm² as measured under a condition where the markingfilm is elongated at a tension speed of 300 mm/min. into an elongationpercentage of from 0 to 10%.

A composite marking film 10 is constituted by the marking film 3 and anapplication film 13 in combination. As shown, the application film 13 isconstituted by a base member 11 and an adhesive layer 12 formed on onesurface of the base member 11 and can be adhered onto the base member 1of the marking film 3. In a step prior to forming the composite markingfilm 10 in combination with the marking film 3, it is desired that theapplication film 13 is provided with a peeling paper applied onto thesurface of the adhesive layer 12, as is generally done in this field ofart. This is to avoid undesired adhesion with each other or with anyother material when the application film 13 is to be preserved in theform of a roll or in any other form, or is to be stuck to the markingfilm 3.

The composite marking film 10 of the present invention has a modulus ofelasticity in a range of from 2 to 28 kgf/mm² as measured under acondition where the composite marking film is elongated at a tensionspeed of 300 mm/min. into an elongation percentage of from 0 to 10%. Itis desired that the composite marking film 10 has a thickness (totalthickness of the marking film 3 and the application film 13, inclusiveof the thickness of any additional layer) of from 110 to 350 μm.

The operation for adhering the above-mentioned marking film or thecomposite marking film onto an article is carried out according to aprocedure that will be described below.

First, an application film comprising a base member and an adhesivelayer is prepared. Next, a marking film comprising an ornamental film(base member) having an adhesive layer and a peeling paper applied tothe side of the adhesive layer is prepared. The application film isstuck to the surface of the marking film without having the adhesivelayer in order to form a composite marking film of the present inventioncomprising the marking film and the application film as a unitarystructure.

Next, the composite marking film is positioned on a predeterminedportion of an article in a manner that the application film is on theupper side and is adhered via the adhesive layer of the ornamental film.According to the present invention, the composite marking film can beintimately adhered onto the surface of the article without developingwrinkles or entrapping air bubbles. After the composite marking film hasbeen adhered, the application film is peeled off the ornamental film ofthe marking film adhered onto the article. As a result, the ornamentalfilm (marking film) 3 is obtained being intimately adhered onto thecurved surface of the article 9 as shown in FIG. 2 which furtherillustrates an over-clear coating 4 that is subsequently applied. Inthis case, the occurrence of inconvenience such as entrapping of airbubbles has been prevented at an end of the ornamental film 3 indicatedby an arrow A.

In the practice of the present invention, no particular limitation isimposed on the base members used for the marking film and theapplication film, provided the base members have flexibility required bythe present invention. Suitable examples of the base member include softvinyl chloride resin, urethane resin, polyolefin resin and polyesterresin and, preferably, soft vinyl chloride resin and urethane resin,though the base member is not necessarily limited thereto only. The basemembers may be constituted by a single kind of the resin, or a laminatedlayer structure may be constituted by using two or more kinds of resinsin combination.

The thicknesses of the base members can be widely changed depending uponthe desired effect but must satisfy the above-mentioned requirements ofthicknesses. As for the marking film, when no over-clear coating hasbeen applied, the thickness of the base material is from 50 to 300 μmand, more desirably, from 50 to 250 μm inclusive of the thickness of theadhesive layer applied to the base member. When the thickness of thebase member becomes smaller than 50 μm, the marking film losesstiffness, and the film as a whole becomes too soft when the partingpaper is peeled off the marking film prior to being used. If desired,the thickness of the base member of the marking film may exceed theupper limit of the above-mentioned range.

Furthermore, the properties of the base member used for the marking filmplay an important role. That is, the base member used for the markingfilm must have a modulus of elasticity of from 2 to 25 kgf/mm² and, morepreferably, from 2 to 5 kgf/mm² as measured under particular elongationconditions, i.e., as measured under a condition where the marking filmis elongated at a tension speed of 300 mm/min. into an elongationpercentage of from 0 to 10%. When the modulus of elasticity of the basemember becomes larger than 25 kgf/mm², the flexibility becomesinsufficient and the ability for tracing the three-dimensional curvedsurfaces is deteriorated. When the modulus of elasticity of the basemember becomes smaller than 2 kgf/mm², on the other hand, the rubberyelasticity becomes insufficient, and wrinkles develop on the outerperiphery of the marking film. It is desired that the base member has amaximum elongation of not smaller than 200% so that the application filmused in combination therewith can be elongated to a sufficient degree.

Similarly, an important role is played by the thickness and propertiesof the marking film accompanied by the application film, i.e., of thecomposite marking film. That is, it is desired that the compositemarking film has a thickness of from 110 to 350 μm and, more preferably,from 180 to 300 μm. When the thickness of the composite marking filmbecomes smaller than 110 μm, there occurs inconvenience such as lack ofstiffness of the composite marking film. When the thickness of thecomposite marking film becomes larger than 350 μm, on the other hand,the stress increases too much in the film, and the ability for tracingthe curved surfaces and the operability are deteriorated.

It is essential that the composite marking film has a modulus ofelasticity of from 2 to 28 kgf/mm² and, more preferably, from 4 to 14kgf/mm² as measured under the same elongation conditions as those forthe above-mentioned marking film. When the modulus of elasticity of thebase member becomes larger than 28 kgf/mm², the flexibility is lost andability for tracing the three-dimensional curved surfaces isdeteriorated. When the modulus of elasticity of the base member becomessmaller than 2 kgf/mm², on the other hand, the rubbery elasticitybecomes insufficient and wrinkles easily develop when the compositemarking film is adhered to the article. It is desired that theapplication film used for the composite marking film has a maximumelongation of not smaller than 200% so that the marking film can beelongated to a sufficient degree depending upon a variety kinds ofarticles.

Concerning the evaluation of ability for tracing the curved surfaces,furthermore, the present inventors have discovered, through experiment,that it can be easily judged which combination of the marking film andthe application film, i.e., which composite marking film would offersatisfactory ability for tracing the curved surfaces without reallysticking the film.

A number of marking films and application films are prepared and arearbitrarily combined together to prepare marking films accompanied by anapplication film, i.e., to prepare composite marking films. The area ofa reference composite marking film is denoted by “1”, and ratios ofareas of the sample composite marking films thereto (referred to as“area ratios”) f(x) and moduli of elasticity (x) of the compositemarking films are found for each of the composite marking films. Then,relationships between the moduli of elasticity and the area ratios areplotted on a graph for each of the composite marking films, and it islearned that there exists a relationship represented by a primaryregression curve between them as expressed by the following formula (1),

f(x)=−0.076x+4.13

Here, favorable ability for tracing the curved surfaces is obtained whenf(x) is 2 or larger and, more preferably, when f(x) is 3 or larger.

When the thickness of the application film is denoted by t1, modulus ofelasticity thereof by m1, thickness of the marking film by t2 and themodulus of elasticity thereof by m2, the modulus of elasticity (x) ofthe composite marking film can be expressed by the following formula(2),

x=m 1×t 1/(t 1+t 2)+m 2×t 2/(t 1+t 2)

Thus, the composite marking film of which combination would offerexcellent ability for tracing the curved surfaces can be judged easily,precisely and highly reliably provided the thicknesses and moduli ofelasticity of the marking film and the application film have been knownwithout the need of conducting the evaluation testing by really stickingthe marking films. The fact that it is made possible to evaluate thedegree of ability for tracing the three-dimensional curved surfaces isan innovative discovery.

There is no particular limitation on the adhesive layer applied onto onesurface or, as required, onto both surfaces of the base members of themarking film and the application film. Therefore, any adhesive agent canbe used as is generally done in this field of art to form the adhesivelayer maintaining any desired thickness relying upon an applicationmethod that is customarily used. Suitable examples of the adhesive agentmay include an acrylic adhesive agent comprising, chiefly, a butylacrylate that has heretofore been used, a rubber-type adhesive agentcomprising, chiefly, a styrene-butadiene rubber (SBR) and the like, anurethane-type adhesive agent, a silicone-type adhesive agent, a vinylacetate-type adhesive agent, and the like agents. The thickness of theadhesive layer formed by applying these adhesive agents can be widelychanged but is, usually, in a range of from 10 to 40 μm and, morepreferably, from 15 to 30 μm.

The adhesive strengths of the adhesive layers, i.e., the adhesivestrength of the application film relative to the marking film and theadhesive strength of the marking film relative to the article, can besuitably selected by taking into consideration a variety of factors suchas base materials, materials of the marking film and the applicationfilm, and environment in which the sticking operation is carried out.The adhesive strength of the application film relative to the markingfilm is generally over a range of from 10 to 800 gf/25 mm as measured incompliance with the standards stipulated under JIS-Z0237. In the finalstep of operation, the application film must be peeled off the markingfilm. Therefore, the adhesive strength must not be larger than theadhesive strength of the marking film relative to the article.Preferably, furthermore, the adhesive strength of the marking filmrelative to the article is in a range of from 0.5 to 4.0 kgf/25 mm asmeasured in compliance with the standards stipulated under JIS-Z0237.

As briefly described earlier, it is desired that the adhesive layers ofthe application film and the marking film are protected by partingpapers until these films are used. There is no particular limitation onthe parting papers used here, and it is allowed to use any parting paperthat has generally been used in this field of art. Suitable examples ofthe peeling paper include woven or nonwoven fabric, paper, or plasticsheet that has been treated so as to be parted. Furthermore, suitableexamples of the parting agent include a silicone-type parting agent andthe like agent.

In general, the marking film is applied with a coloring layer containingan ink to produce ornamental appeal or with a transparent resin layer(so-called clear layer) in order to impart luster or to improveadhesiveness of the over-clear coating. In this case, too, any kind ofink or transparent resin can be used provided it has properties lyingwithin ranges contemplated by the present invention. Suitable examplesof the ink include those of the urethane type, acrylic type and vinylchloride type. Suitable examples of the transparent resin include thoseof the urethane type, acrylic type and fluorine type. There is noparticular limitation on the thicknesses of the coloring layer and theclear layer. Generally, however, the thicknesses of these layers lie ina range of from 5 to 40 μm and, more preferably, in a range of from 5 to20 μm.

The marking film can be used in such applications as being stuck to afuel tank of a motorcycle having a three-dimensional curved surface.After the marking film is stuck, in this case, the surface of the fueltank inclusive of the marking film may often be covered with theover-clear coating. The over-clear coating works to protect the markingfilm from being peeled off or rubbed and to further improve theornamental appeal. Here, when the marking film is too thick, air bubblesare entrapped at the ends of the film impairing the appearance. When theover-clear coating is applied, therefore, it is desired that thethickness of the marking film is not larger than 120 μm and, morepreferably, not larger than 100 μm.

EXAMPLES

The invention will now be described by way of working examples. Here,however, it should be noted that the invention is in no way limited tothese examples only.

Example 1

Two kinds of application films AP1 and AP2 were prepared according tothe procedure described below.

Application Film 1 (AP1):

Application tape “Tape #331 (production lot No. 33080326)” having a basemember of a vinyl chloride resin film that is commercially availablefrom Sumitomo 3M Co.

The base member of this film is the one prepared by adding 33 parts byweight of dioctyl phthalate (as a plasticizer) and 2 parts by weight ofan epoxylated soybean oil (as a stabilizer) to 100 parts by weight of avinyl chloride resin, and subjecting the mixture into the calendermolding so as to acquire a thickness of 68 μm. The adhesive layer isformed by uniformly applying an acrylic adhesive agent comprisingchiefly a butyl acrylate onto one surface of the base member maintaininga thickness of 7 μm.

Application Film 2 (AP2):

Commercially available under the trade name “SCT1010J” from Sumitomo 3MCo.; Prepared by adding 33 Parts by weight of dioctyl phthalate (as aplasticizer), 15 parts by weight of a polyester-type plasticizer and 2parts by weight of an epoxylated soybean oil (as a stabilizer) to 100parts by weight of a vinyl chloride resin. The obtained mixture wascalender-molded to prepare a vinyl chloride resin film having athickness of 100 μm. Then, an acrylic adhesive agent comprising chieflya butyl acrylate was uniformly applied maintaining a thickness of 15 μmonto one surface of the obtained vinyl chloride resin film.

Example 2

Five kinds of marking films MK1, MK2, MK3, MK4 and MK5 were preparedaccording to the procedure described below.

Marking Film 1 (MK1):

“Scotchcal™ 3650” film commercially available from Sumitomo 3M Co. Thismarking film uses a relatively hard soft vinyl chloride resin as a basemember and has a thickness of 50 μm. The adhesive layer is formed byuniformly applying an acrylic adhesive comprising chiefly a2-methylbutyl acrylate maintaining a thickness of 30 μm onto one surfaceof the base member.

Marking Film 2 (MK2):

“Scotchcal™ CS-206 F02” film commercially available from Sumitomo 3M Co.This marking film uses a slightly flexible soft vinyl chloride resin asa base member and has a thickness of 106 μm. The adhesive layer isformed by uniformly applying an acrylic adhesive comprising chiefly a2-methylbutyl acrylate maintaining a thickness of 35 μm onto one surfaceof the base member.

Marking Film 3 (MK3):

“Scotchcal™ OT-305W” film commercially available from Sumitomo 3M Co.This marking film uses a flexible soft urethane resin as a base memberand has a thickness of 30 μm. The adhesive layer is formed by uniformlyapplying an acrylic adhesive comprising chiefly a butyl acrylatemaintaining a thickness of 20 μm onto one surface of the base member.

Marking Film 4 (MK4):

“Scotchcal™ PU-295T” film commercially available from Sumitomo 3M Co.This marking film uses a soft and rubbery elastic urethane resin as abase member and has a thickness of 140 μm. The adhesive layer is formedby uniformly applying an acrylic adhesive comprising chiefly a butylacrylate maintaining a thickness of 40 μm onto one surface of the basemember.

Marking Film 5 (MK5):

Commercially available under the trade name “GMW8000J” from Sumitomo 3MCo.; Prepared by adding 0.9 Equivalents of an isophoron diisocyanate and0.2 equivalents of a hexamethylene diisocyanate to a polycarbonate-typepolyol (OHV=14.7) to prepare a coating solution. The thus obtainedcoating solution was formed into a thin film by bar coating and wereheated and cured. There was obtained a rubbery elastic urethane resinfilm having a thickness of 70 μm. Then, an acrylic adhesive comprisingchiefly a butyl acrylate was uniformly applied maintaining a thicknessof 30 μm onto one surface of the obtained urethane resin film.

Example 3

In order to evaluate the properties of the marking film and thecomposite marking film of the present invention, experiments wereconducted according to a procedure described below. The moduli ofelasticity of the films were measured under a condition where the filmswere elongated at a tension speed of 300 mm/min into an elongationpercentage of 0 to 10%.

Experiment 1

The application films prepared in Example 1 were stuck to the markingfilms prepared in Example 2 and were intimately adhered thereto to asufficient degree. The films were combined together in a manner as shownin Table 1. The obtained composite marking films were cut into circleshaving diameters of from 50 to 150 mm maintaining a difference of 10 mmrelative to one another. Peeling papers of the marking films were peeledoff the circular films, and the marking films were stuck to spheres(made of an acrylic resin) having a diameter of 150 mm by using asqueegee. It became difficult to stick the circular films onto thespheres as the diameter of the circular films increased. Table 1 showscritical points (maximum diameters of the circular films that can bestuck) at where the operation efficiency for sticking the circular filmsof the composite marking films decreases and wrinkles start developingtogether with the area ratios of when the area of a reference compositemarking film (combination of AP1 and MK1) is set to be “1”. Table 1further shows moduli of elasticity measured from the composite markingfilms.

TABLE 1 max. application marking diameter area elasticity film film (mm)ratio (kgf/mm²) AP1 MK1  60 1 46 AP1 MK2  70 1.36 25.1 AP1 MK3  80 1.7835.6 AP1 MK4 110 3.36 11.8 AP1 MK5 100 2.78 17.9 AP2 MK1  80 1.78 28.1AP2 MK2 100 2.78 17.1 AP2 MK3  90 2.25 20.5 AP2 MK4 120 4 5.8 AP2 MK5120 4 5.1

As will be obvious from the results of Table 1, use of the marking filmand the composite marking film of the present invention makes itpossible to improve the operation for sticking the marking film and toprevent the occurrence of defects such as wrinkles compared with whenthe conventional marking films are used.

From the results of Table 1, furthermore, a graph shown in FIG. 3 isobtained by plotting relationships between the area ratios and themoduli of elasticity. From these results, the relationships between thearea ratios and the moduli of elasticity can be expressed by a primaryfunction as given by the following formula (1),

f(x)=−0.076x+4.13

where f(x) is a ratio of the area of a reference composite marking filmthat is regarded to be “1” to the area of a sample composite markingfilm, and x is a modulus of elasticity of a composite marking film. Thisformula makes it possible to judge the composite marking film of whichcombination will offer excellent ability for tracing the curved surfaceseasily, highly precisely and highly reliably provided the thicknessesand the moduli of elasticity of the marking film and the applicationfilm have been known without conducting the evaluation testing by reallysticking the marking film.

Based upon the results of Table 1, furthermore, the inventors haverearranged the relationships between the moduli of elasticity and thearea ratios of the marking films concerning different composite markingfilms (combinations of marking films and application films), and haveobtained the results as shown in Table 2 and a graph as plotted in FIG.4. In FIG. 4, graphs I represent area ratios of when AP1 is used, graphsII represent area ratios of when AP2 is used, and a graph III representsthe modulus of elasticity.

TABLE 2 marking area ratio area ratio elasticity film (using AP1) (usingAP2) (kgf/mm²) MK1 1 1 62.06 MK3 1.78 1.26 50.38 MK2 1.36 1.56 24.71 MK52.78 2.25 3.37 MK4 3.36 2.25 2.47

From these results, it will be understood that the area of the markingfilm of the present invention that can be stuck increases with adecrease in the modulus of elasticity of the marking film irrespectiveof the kind of the application film.

Experiment 2

The procedure of the above Experiment 1 was repeated. In thisexperiment, however, the moduli of elasticity of the application filmsand the marking films as well as the moduli of elasticity of thecomposite marking films were measured as shown in Table 3. Furthermore,the moduli of elasticity (x) of the composite marking films werecalculated in compliance with the following formula (2),

x=m 1×t 1/(t 1+t 2)+m 2×t 2/(t 1+t 2)

In the above formula, t1 is the thickness of the application film, m1 isthe modulus of elasticity thereof, t2 is the thickness of the markingfilm and m2 is the modulus of elasticity thereof. The measured resultsand the calculated results are shown in Table 3 and in FIG. 5. In FIG.5, F denotes measured moduli of elasticity and C denotes calculatedmoduli of elasticity.

TABLE 3 marking elasticity applica- elasticity of of elasticityelasticity tion application marking marking (kgf/mm²) (kgf/mm²) filmfilm film film found calculated AP1 30.89 MK1 62.06 46 47 AP1 30.89 MK224.71 25.1 26.9 AP1 30.89 MK3 50.38 35.6 38.7 AP1 30.89 MK4 2.47 11.812.6 AP1 30.89 MK5 3.37 17.9 15.2 AP2 7.07 MK1 62.06 28.1 30.2 AP2 7.07MK2 24.71 17.1 17 AP2 7.07 MK3 50.38 20.5 20.6 AP2 7.07 MK4 2.47 5.8 5.3AP2 7.07 MK5 3.37 5.1 4.2

From these results, it can be understood that in the case of thecomposite marking films of the present invention, the ability fortracing the curved surfaces can be estimated provided the moduli ofelasticity and thicknesses of the application films and the markingfilms have been known without the need of really combining the two filmstogether to prepare composite marking films and without really stickingthe composite marking films.

Experiment 3

Experiment was conducted according to the following procedure in orderto evaluate the adaptability of the over-clear coating to the markingfilm of when the over-clear coating is applied onto the marking film.

As an article (base member to which the marking film is to be stuck),there was provided a plate coated with melamine white of Paltech Co. Themarking films MK1 to MK5 (measuring 50 mm×50 mm) prepared in Example 2above were stuck onto the articles together with the application filmAP1 prepared in Example 1 above with pressure. A squeegee was used toassist the sticking operation.

After the sticking operation has been completed, the application filmAP1 was peeled off the marking films which were then left to stand atroom temperature for 48 hours. Then, the over-clear coating material (ablend of “Beamcoat No. 1500 Clear HM” and a high-urethane curing agent“HL-M” manufactured by Nippon Yushi Co. at a ratio of 5:1) was sprayedonto the whole article inclusive of the surface of the marking film soas to form a film having a dry thickness of 60 pin followed by drying.After the over-clear coating has been applied, the appearance of themarking films was observed by eyes, and the results were obtained asshown in Table 4.

TABLE 4 marking film film thickness (μm) appearance MK3  50 no problemMK1  80 no problem MK5 100 no problem MK2 140 bubbles in film edge MK4180 bubbles in film edge

From the results of Table 4, it will be understood that air bubbles areentrapped to deteriorate the appearance of the over-clear coating whenthe thickness of the marking film becomes great.

As described above, the marking film of the present invention can beeasily stuck even onto rugged portions or steeply curvedthree-dimensional surfaces such as fuel tanks, fenders, etc. withoutaccompanied by defects such as occurrence of wrinkles or entrapping ofair bubbles, maintaining very favorable operation efficiency. Even whenthe over-clear coating is applied after the marking film has been stuck,there does not occur such inconvenience as entrapping of air bubbles atthe ends of the film. Moreover, the composite marking film of thepresent invention which is stiff can be stuck favorably facilitating thepositioning operation and avoiding such an inconvenience that the filmsadhere together during the operation. Furthermore, the composite markingfilm of the present invention avoids the probability of being damagedafter it has been stuck.

What is claimed is:
 1. A composite marking film for transferring amarking component to an article, comprising: an application filmcomprising a first base member and a first pressure sensitive adhesivelayer on an outer surface of the first base member; and a marking filmhaving a first outermost surface temporarily adhered to the firstadhesive layer of the application film, wherein the marking filmcomprises a second base member and a second pressure sensitive adhesivelayer on an outer surface of the second base member, wherein the secondpressure sensitive adhesive layer forms a second outermost surface ofthe marking film; wherein the composite marking film has a modulus ofelasticity in the range of from about 2 kgf/mm² to about 28 kgf/mm² asmeasured under a condition where the composite marking film is elongatedat a tension speed of 300 mm/min. into an elongation percentage in therange of from 0 to about 10%, and wherein the marking film alone has amodulus of elasticity in the range of from about 2 kgf/mm² to about 25kgf/mm² as measured under a condition where the composite marking filmis elongated at a tension speed of 300 mm/min, into an elongationpercentage in the range of from 0 to about 10%, wherein said first basemember comprises vinyl chloride resin; said second base member comprisesvinyl chloride resin or urethane resin; said first adhesive layercomprises a butyl acrylate; and said second adhesive layer comprises abutyl acrylate or a 2-methylbutyl acrylate.
 2. The composite markingfilm according to claim 1, wherein the composite marking film has anoverall thickness in the range of from about 110 μm to about 350 μm. 3.The composite marking film according to claim 1 in combination with anarticle, wherein said composite marking film is adhered to said articlevia said second pressure sensitive adhesive layer.
 4. The compositemarking film according to claim 3, wherein said composite marking filmis adhered onto a rugged portion or steeply curved three-dimensionalsurface of said article.
 5. The composite marking film according toclaim 1, wherein the adhesive strength of the second pressure sensitiveadhesive layer is from 0.5 to 4.0 kgf/25 mm, and the adhesive strengthof the first pressure sensitive adhesive layer is from 10 to 800 gf/25mm.
 6. The composite marking film according to claim 3, wherein saidarticle comprises a motorcycle fuel tank or a fender.
 7. The compositemarking film according to claim 1, wherein said second base member has amaximum elongation of at least 200%.
 8. The composite marking filmaccording to claim 1, wherein said marking film has a total thickness inthe range of from about 50 μm to about 300 μm.
 9. The composite markingfilm according to claim 1, further comprising a release liner on thesecond pressure sensitive adhesive layer.
 10. The composite marking filmaccording to claim 1, wherein an adhesive strength of the secondpressure sensitive adhesive layer is greater than an adhesive strengthof the first pressure sensitive adhesive layer.